Cleaning and descaling apparatus

ABSTRACT

An abrading apparatus for cleaning an outer surface of an elongate member, such as a wire. An endless abrasive sanding belt is rotated about a plurality of rollers and orbited about the elongate member. Drive components for both rotating the belt about the rollers as well as orbiting the belt about the elongate member are isolated in an enclosed drive casing containing lubricating fluid, such as oil. A first roller which mounts the endless sanding belt is fixed in a rotatable eccentric support. This eccentric support allows the tension of the endless belt to be adjusted by rotating the eccentric support in one of two directions. One of the rollers includes a mounting portion and a belt supporting portion, with the mounting portion being axially offset or eccentric with respect to the belt supporting portion. A belt engagement and disengagement mechanism is connected to the eccentric mounting portion of the idler roller to allow rotation of the eccentric mounting portion in two directions.

BACKGROUND OF THE INVENTION

The present invention generally relates to abrasively cleaning burrs,scales and the like from elongate cylindrical objects such as metallicrod, pipe and, especially, continuous strands of wire.

One known type of machine for abrasively cleaning a continuous wirestrand uses a rotating sanding belt which orbits about the wire as thewire is pulled past and against the belt. A machine of this basicvariety is disclosed in U.S. Pat. No. 3,559,348. This machineeffectively abrades and cleans the entire outside or circumferentialsurface of the wire by simply pulling the wire through the machine. Twotypes of rotation and, therefore, two types of drives are used in thismachine. One drive rotates an endless sanding belt mounted transverse toand in contact with the wire, while another drive orbits the entiresanding belt about the wire such that the entire outer circumference isabraded as the wire travels past the sanding belt.

While machines of this type have been generally quite efficient andsuccessful, certain areas for further improvements exist and areaddressed by the present invention. One involves the life of the drivecomponents used to both rotate and orbit the sanding belt with respectto the wire strand. As these machines are often continuously used inhigh volume production runs, the drive components tend to wear out fromthe combination of the continuous operation of the machine and theadverse effects of having the gritty by-products of the descalingoperation infiltrate the drive mechanisms.

Another problem of past abrading machines of the type disclosed in U.S.Pat. No. 3,559,348 involves the ability to tension the sanding belt tomaintain proper tracking and to maintain forceful contact between thebelt and the wire strand as the belt is orbited about the wire. Thetensioning system disclosed in U.S. Pat. No. 3,559,348 is quitecomplicated in design and has many components which increase the cost ofthe machine and the propensity for the machine to break down. Anotherneed involves the ability to easily remove and replace the sanding belt.

There is, therefore, a need for an abrading machine which is relativelymore simple in construction than past machines, but which has variousadvantages over such past machines. These advantages would includelonger drive life, simpler belt tensioning or tracking adjustment, andeasier belt removal and replacement.

SUMMARY OF THE INVENTION

To these ends, the present invention provides an abrading apparatus forcleaning an outer surface of an elongate member, such as a wire, withthe apparatus including an endless abrasive sanding belt rotated about aplurality of rollers and orbited about the elongate member. Inaccordance with one aspect of this invention, drive components for bothrotating the belt about the rollers as well as orbiting the belt aboutthe elongate member are isolated in an enclosed drive casing containinglubricating fluid, such as oil. This case therefore not only maintainsthese drive components isolated from the abrasive byproducts of thecleaning operation, but lubricates the components at the same time. Astationary housing contains the drive casing, the endless sanding beltand the rollers. The casing is mounted to a support member of thehousing by bearings and is rotated to orbit the endless sanding beltabout the elongate member. The rollers are fixed in bearings mounted inthe casing.

In a second aspect of the invention, a first roller which mounts theendless sanding belt is fixed in a rotatable eccentric support. Thiseccentric support allows the tension of the endless belt to be adjustedby rotating the eccentric support in one of two directions. Rotation inone direction moves the first roller toward a second roller and rotationin the opposite direction moves the first roller away from the secondroller. In the preferred embodiment, the first roller is an idler rollerwhile the second roller is a driven roller. The eccentric support formspart of a bearing assembly which mounts the first roller to the drivecasing. The eccentric support is connected to a handle for manuallyturning the eccentric support to adjust the belt tension or tracking anda selectively engageable lock is provided for locking the handle and theeccentric support in place.

In a third aspect of the invention, one of the rollers includes amounting portion and a belt supporting portion, with the mountingportion being axially offset or eccentric with respect to the beltsupporting portion. Preferably, it is the first or idler roller whichincludes this eccentric mounting portion. A belt engagement anddisengagement mechanism is connected to the eccentric mounting portionof the idler roller to allow rotation of the eccentric mounting portionin two directions. Rotation in one direction moves the roller portion,i.e., the idler roller toward the drive roller to a belt releaseposition and rotation in an opposite direction moves the idler rolleraway from the drive roller to a belt engagement position. A linkageassembly is connected to the eccentric mounting portion and is actuableby a handle to effect rotation of the eccentric mounting portion. Thehandle is pivotally mounted to a handle support, which is preferably thedrive casing. The linkage assembly more specifically includes a firstlink connected to the eccentric mounting portion of the idler roller anda second link pivotally connected between the first link and the handle.A spring is connected between the first link and the handle to retainthe linkage assembly and therefore the idler roller in one of the twopositions.

The belt drive and the orbital drive of this invention comprise a maingear and a drive gear operatively connected together such that the drivegear rotates about the main gear. The drive gear is rigidly connected tothe drive roller to rotate the drive roller as the drive gear rotatesabout the main gear. In the preferred embodiment, the main gear and thedrive gear are connected by a gear belt or "silent chain" and the maingear is stationary. A drive shaft is rigidly connected to the drivecasing and operatively connected to a motor output for rotating thedrive shaft, the casing and any support provided for the elongate memberbeing cleaned. Preferably, the support for the elongate member is onewhich is fixed in axial relationship to the drive shaft and the driveshaft further includes an axial bore which receives the elongate member,such as a wire, being fed linearly therethrough.

Further objects and advantages of this invention will become morereadily apparent to those of ordinary skill upon review of the followingdetailed description of the preferred embodiment taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a cleaning and descaling apparatusconstructted in accordance with the present invention;

FIG. 2 is a cross sectional view taken along line 2--2 of FIG. 1;

FIG. 3 is a crossesectional view taken generally along line 3--3 of FIG.2;

FIG. 3A is a view similar to FIG. 3 but showing the belt in a disengagedposition;

FIG. 4 illustrates the belt tensioning mechanism and the belt releasemechanism of the invention and is taken generally along 4--4 of FIG. 3;

FIG. 5 is a perspective view of a link in the belt release mechanism andits attachment to the idler roller of the apparatus;

FIG. 6 is a perspective view of the support for the elongate member andits attachment to the drive shaft of the apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a cleaning and descaling apparatus 10 is shown andgenerally includes an upper housing 12 and a lower support base 14.Upper housing 12 includes a cover 16 which may be opened and closed by ahinged connection 18 to allow access to the various components of theapparatus inside as will be discussed below. A counterweight 20 isprovided for assisting in opening cover 16 and is connected to athreaded rod 22 connected by a pivot 23 on a support 25 extending fromupper housing 12. At the upper end of threaded rod 22, a compressionspring 24 is mounted between an adjustment nut 26 and a spring mount 28connected to counterweight 20. A stop 30 is provided on support 25 forstopping counterweight 20 and cover 16 at a fully opened position.Adjustment nut 26 may be threaded and moved upwardly and downwardlyalong threaded rod 22 to change the compression of spring 24 and therebychange the counterbalancing effect of counterweight 20.

As further shown in FIG. 1, a motor 34 is provided for operating variouscomponents within housing 12 as will be described further below. Motor34 is fixed to a mount 36 which is supported by a pivot connection 38 ona support 40 on one side and by turn buckles 44 (only one of which isshown) pivotally connected between a lower support 46 extending frombase 14 and an outside edge portion 42 of mount 36.

Referring now mainly to FIG. 2, a drive belt 50 extends from an output51 of motor 34 to a drive sheave 52. Drive sheave 52 is rigidly fastenedto a drive shaft 54 which extends into housing 12. Specifically, atapered mounting 56 is connected to drive shaft 54 by a key 58 intodrive sheave 52 by fasteners 60, 62, only two of which are shown. Driveshaft 54 includes a central bore 64 for receiving the elongate member,such as a wire 66 to be fed in a linear fashion therethrough intohousing 12 where it is abrasively cleaned, in a manner to be describedbelow. Wire guides 68, 70 are provided at opposite ends of drive shaft54 and include carbide bushings 72, 74 for guiding and restraininglateral movement of wire 66. A brake assembly 78 is provided forstopping the rotation of drive shaft 54 and specifically comprises aconventional disk 80 and caliber assembly 82.

Still referring to FIG. 2, a sealed drive casing 84 is rotatable mountedwithin housing 12 and rotated by drive shaft 54. Drive casing 84includes an annular cover 86 and a pair of side plates 88, 90 with cover86 being fastened onto side plates 88, 90 by a connecting clamp orbracket 92. A pair of annular seals 94, 96 are disposed between theperiphery of the respective side plates 88, 90 and annular cover 86.Annular cover is provided with a port 98 for filling drive casing 84with lubricating fluid such as oil.

A flange portion 100 of drive shaft 54 is rigidly secured to side plate90 of drive casing 84 by fasteners 102, 104, only two of which areshown. Drive casing 84 is supported for rotation on a rigid, stationarysupport 106 within housing 12 by a pair of bearings 108, 110. Bearings108, 110 are suitably fixed on support 106 by bearing holders 112, 114and respective spacer members 116, 118, 120. An annular seal 122 isprovided between bearing holder 114 and spacer member 120. An annularshield 124 is fixed to bearing holder 114 and surrounds the casingsupport 106 to keep excessive dust, etc., from entering the area of seal122. Drive shaft 54 is also supported for rotation by a further bearing126 held within a bearing mount assembly 128 which is rigidly fastenedto housing 12 by bolts 130, only one of which is shown in FIG. 2. Anannular seal 132 is provided between bearing mount assembly 128 and amounting portion 134 of drive shaft 54. Finally, a vent 136 is providedfor venting housing 12 when apparatus 10 is in use.

As also shown in FIG. 2, secured for rotation to drive casing 84 are apair of rollers 140, 142. First roller 140 is preferably an idlerroller, while second roller 142 is a drive roller. An endless sandingbelt 144 having an abrasive outer surface 146 is mounted on rollers 142,144. An elongate wire guide or support 148 is mounted therebetween forrotation with drive shaft 54.

Referring briefly to FIG. 6, wire guide or support 148 more specificallycomprises an elongate member having a recess 150 for accommodatingendless sanding belt 144 without the sanding belt 144 contacting wireguide 148. One or more carbide strips 152 are fixed to wire guide 148with fasteners 154, 156 and are partially circular in cross sectionalshape such that they bear against the outside surface of wire 66. Amounting flange 158 is formed at one end of wire guide 148 and isrigidly secured to flange portion 100 of drive shaft 54 by screwfasteners 160, 162. On the opposite side of wire guide 148 from flangeportion 158, a restraining plate 164 is affixed to flange portion 1 00by a separate screw fastener 166. Finally, the outer end of wire guide148 includes a cylindrical carbide bushing 168 which further guides wire66 as it travels linearly through wire guide 148.

Turning back to FIG. 2, the rotational and orbital drive of endlesssanding belt 144 will now be described. Roller 140 is rotationallysupported by an eccentric rod 170. Eccentric rod 170 includes both aroller portion 172 and a mounting portion 174 with portions 172, 174being axially offset from each other as best shown in FIG. 4. Roller 140more specifically comprises a steel cylindrical core 180 having africtional coating, such as a rubber or polymeric coating 182 whichfrictionally engages endless sanding belt 144. Roller 140 is supportedfor rotational movement on rod portion 172 by a pair of roller bearings176, 178. Steel core 180 includes an inner stepped portion 184 againstwhich roller bearings 176, 178 are held. Roller bearing 176 is heldagainst one side of stepped portion 184 by a retaining plate 186 and afastener 188 which extends into roller portion 172 or rod 170. Rollerbearing 178 is held between the other end of stepped portion 184 and asleeve or larger diameter portion 190 of roller portion 172. The rollerportion also includes, opposite the sleeve portion 190, an enlargeddiameter 191 against which the entire roller assembly (roller bearings176, 178 and sleeve 190) is secured by the fastener 188.

Mounting portion 174 of eccentric rod 170 is held for rotation withincasing 84 by a pair of spherical bearings 192, 194. Bearings 192, 194only allow rotation during adjustment of the tracking or tension ofsanding belt 144 as will be described below. Spherical bearings 192, 194are respectively held in bearing mounts 196, 198 and a cylindrical oilseal 199 is disposed therebetween. As will be discussed below, a sandingbelt engagement and disengagement mechanism 200 is connected to mountingportion 174 or eccentric rod 170 and a belt tensionsing or trackingmechanism 202 is connected to bearing mount 198 for providing a finetracking or tensioning adjustment for sanding belt 144 as will also bediscussed below.

A straight rod 204 mounts second roller 142 and provides rotationaldriving of sanding belt 144 about rollers 140, 142. Rod 204 is rigidlyaffixed to roller 142 by a center bushing 206 which is secured to anouter end of rod 204 by a bolt 208 and an end bushing or mount 210 whichis press fit or otherwise rigidly secured to an inner end of roller 142.Like roller 140, roller 142 is preferably formed with a steel core 207having a frictional coating, such as a rubber or polymeric coating 209.A steel core 207 includes a stepped portion 211 against which bushings206, 210 are mounted. A key 212 fixes end bushing 210 to shaft 204 forrotation therewith. A seal 214 is provided within a seal holder 216 andbetween end bushing 210 and a first roller bearing 218 of a pair ofroller bearings 218, 220 which mount an inner end of rod 204 withindrive casing 84. Respective bearing mounts 222, 224 hold bearings 218,220.

A drive gear 226 is rigidly secured to drive rod 204 within drive casing84, preferably by a key 228. A main gear 230 is rigidly secured tostationary casing support 106 by another key 232. An endless gear beltor silent chain 234 extends around both a drive gear 226 and main gear230 and includes teeth which engage respective teeth 236, 238 on drivegear 226 and main gear 230. It will thus be appreciated that, as driveshaft 54 is rotated, the entire drive casing 84 will be rotated aboutstationary drive casing support 106 because of the rigid connectionbetween flange portion 100 or drive shaft 54 and side plate 90 of drivecasing 84. This will likewise rotate drive gear 226 about the stationarymain gear 230 and, at the same time, gear belt or silent chain 234 willrotate drive gear 226 about the axis of drive rod 204, thereby rotatingdrive rod 204 and roller 142. As wire guide 148 is also rigidly securedto drive shaft 54, it too will rotate about wire 66 as it supports wire66 from a side always opposite to abrasive surface 146 of sanding belt144.

Referring now to FIGS. 3 and 4, belt engagement and disengagementmechanism 200 more specifically comprises a linkage mechanism 240 whichis connected to eccentric rod 170 and, more particularly, to mountingportion 174 thereof. As best shown in FIGS. 3 and 3A, linkage assembly240 comprises a handle 242 which is affixed to drive casing side plate88 by a pivot connection 244 and is further connected at its outer endto a connecting link 246 by a second pivot connection 248. The oppositeend of connecting link 46 is connected to a crank 250 by a pivotconnection 252 which rotates eccentric rod 170 (FIG. 4). Referring nowbriefly to FIG. 5, crank 250 is connected to mounting portion 174 ofeccentric rod 170 by way of a recess or slot 254 contained in crank 250which receives a projection 256 extending outwardly from the end ofmounting rod portion 174. As best shown in FIG. 2, mounting portion 174of eccentric rod 170 receives a threaded fastener 258 which extendsthrough a hole 260 in crank 250 and is tightened into a threaded hole262 in the end of mounting portion 174 (FIG. 5). As further shown inFIGS. 3, 3A and 4, the head end 264 of fastener 258 secures the crank250 onto the end of mounting rod portion 174. A spring 266 is connectedbetween a spring pin 268 which is an extension on the end of fastener258 and a second spring pin 270 secured to handle 242. It will beappreciated that with spring 266 disposed just above pivot connection248 as shown in FIG. 3, the force of spring 266 helps maintain linkageassembly 240 in the engaged position shown in FIG. 3. With spring 266disposed below pivot connection 248, linkage assembly 240 is maintainedin the disengaged position as shown in FIG. 3A. Movement of handle 242by an operator in a downward direction pivots crank 250 clockwise asshown in FIG. 3 thereby also rotating mounting portion 174 of eccentricrod 170 clockwise about the axis thereof and, at the same time, rotatingroller portion 172 of eccentric rod 170 about the axis of mountingportion 74 in an upward direction or toward roller 142 (FIG. 2). Thisreleases belt 144 as shown in FIG. 3A such that belt 144 may be removedand replaced. Once belt 144 has been replaced or mounted onto rollers140, 142, handle 242 may again be moved to its upward position as shownin FIG. 3 thereby rotating crank 250 in a counterclockwise direction andmoving roller portion 72 of eccentric rod 170 downwardly about the axisof mounting portion 174 to cause roller 140 to engage belt 144 and applythe necessary tension.

Still referring to FIGS. 3, 3A and 4, a belt tensioning or trackingmechanism 202 is also provided to provide a fine adjustment to thetension of belt 144 to thereby optimize the tracking of belt 144 aboutrollers 140, 142. Specifically, belt tensioning or tracking mechanism202 includes a handle 272 which is connected to bearing mount 198 by apair of pins 274, 276 which extend from a respective pair of arms 278,280 of handle 272. Pins 274, 276 engage two holes 282 selected from aplurality of such holes 282 on an outer periphery of bearing mount 198.Bearing mount 198 includes an eccentric mount as will be appreciatedfrom FIG. 2 and is mounted for rotation within side plate 88 of drivecasing 84. It will be appreciated from FIG. 2 that rotation of bearingmount 198 by way of handle 272 will move eccentric rod 172 slightlyupward or downward depending on the direction of rotation such thattension applied to belt 144 will be slightly increased or decreased byrelative upward or downward movement of roller 140 with respect toroller 142. In this regard, bearing 192 provides enough "play" or, inother words, allows enough upward and downward movement as viewed inFIG. 2 to allow this fine adjustment to be made. As further shown inFIGS. 3 and 3A, a curved slot 284 is provided in handle 272 andcooperates with a clamping assembly 286 to secure handle 272 and,therefore, bearing mount 198 in the desired position. In this regard, aring 288 bears against the outside of handle 272 on opposite sides ofslot 284 as shown in FIGS. 3 and 3A, while a nut 290 is provided on theopposite side of clamping assembly 286 to tighten the assembly 286 downand hold handle 272 in a fixed position. It will be appreciated that anaccess may be provided into drive casing 84 to allow tightening of nut290 or, alternatively, nut 290 may be provided on the outside of handle272 adjacent slot 284.

Operation

Although the operation of apparatus 10 should be understood by those ofskill in the art from the foregoing description, a brief description ofthe operation will be provided for clarity. Prior to the operation ofapparatus 10, endless sanding belt 144 may be mounted onto rollers 140,142 by moving belt engagement disengagement mechanism 200 into thedisengaged position shown in FIG. 3A. Belt 144 may then be tensionedbetween rollers 140 and 142 by moving mechanism 200 into the positionshown in FIG. 3 and fine adjustment of the belt tension may be performedby loosening clamp assembly 286 and appropriately rotating handle 272 toadjust bearing mount 198 to thereby move roller rod portion 172 ofeccentric rod 170 either slightly upward toward roller 142 or downwardand away from roller 142 depending on whether less or more tension isrequired. Referring to FIG. 2, drive shaft 54 is rotated by drive belt50 and drive sheave 52. Rotation of drive shaft 54 rotates drive casing84 about casing support 106 via bearings 108, 110. This rotates drivegear 226 about stationary main gear 230 thereby orbiting rollers 140,142 and sanding belt 144 and also rotating wire guide 148 about wire 66.At the same time, gear belt or silent chain 234 rotates drive gear 26and therefore drive rod 204 and drive roller 142 to rotate endlesssanding belt 144 about rollers 140, 142. During this operation, wire 66is drawn in a linear fashion through carbide bushing 72, central bore 64of drive shaft 54, carbide bushing 74, wire guide 148 which includescarbide bushing strips 152 and, finally, carbide bushing 168, all ofwhich support wire 66 as sanding belt 144 bears and rotates against theentire outer peripheral surface thereof during the orbiting operation.

Although a detailed description of a preferred embodiment of thisinvention has been provided above, it will readily appreciated by thoseof ordinary skill in the art that many modifications and substitutionsof components may be made without departing from the spirit and scope,of the invention. It is therefore Applicant's intention to only be boundby the scope of the claims appended hereto and not to the specificdetails provided in this specification.

What is claimed is:
 1. An abrading apparatus for cleaning an outersurface of an elongate member, the apparatus comprising:an elongatesupport having a central axis for supporting said elongate member; anendless belt having an abrasive surface and mounted for rotation betweenfirst and second spaced apart rollers such that said abrasive surface isdisposed adjacent said elongate support; a belt driving mechanismoperatively connected to said first and second rollers for rotating saidrollers and said belt; an orbital drive mechanism connected to saidfirst and second rollers for rotating said endless belt and said rollersabout said elongate member; and, a sealed casing having a radiallyoutermost portion rotatable about said axis containing and isolatingsaid orbital drive mechanism, said sealed casing containing lubricatingfluid for said orbital drive mechanism.
 2. The apparatus of claim 1wherein said orbital drive mechanism comprises a main gear and a drivegear operatively connected together such that said drive gear rotatesabout said main gear, said drive gear further being rigidly connected tosaid first roller to rotate said first roller upon rotation of saiddrive gear about said main gear.
 3. The apparatus of claim 2 whereinsaid main gear and said drive gear are connected by a gear belt.
 4. Theapparatus of claim 2 further comprising a drive shaft rigidly connectedto said casing and said elongate support and operatively connected to amotor output for rotating said drive shaft, said casing and saidelongate support.
 5. The apparatus of claim 4 wherein said drive shaftincludes an axial bore for receiving said elongate member, and saidelongate support is fixed in axial relationship to said drive shaft. 6.The apparatus of claim 5 further comprising a stationary housing forenclosing said casing, said endless belt and said rollers, wherein saidmain gear is rigidly connected to a support member of said housing andsaid casing is mounted to the support member of said housing by bearingsand said drive shaft rotates said drive gear about said main gear. 7.The apparatus of claim 1 wherein said rollers are fixed in bearingsmounted in said casing.
 8. An abrading apparatus for cleaning an outersurface of an elongate member, the apparatus comprising:an elongatesupport for supporting said elongate member; an endless belt having anabrasive surface and mounted for rotation between a pair of spaced apartrollers such that said abrasive surface is disposed adjacent saidelongate support; a belt driving mechanism operatively connected to saidrollers for rotating said rollers and said belt; an orbital drivemechanism connected to said rollers for rotating said endless belt andsaid rollers about said elongate member; and, wherein one of saidrollers is fixed in a rotatable eccentric support for allowing tensionof said endless belt to be adjusted, whereby rotation of the eccentricsupport in one direction moves said one roller toward the other rollerand rotation of the eccentric support in an opposite direction movessaid one roller away from the other roller.
 9. The apparatus of claim 8wherein the eccentric support forms part of a bearing assembly whichmounts said one roller to said casing.
 10. The apparatus of claim 9wherein said one roller includes an eccentric mounting portion which issupported by said bearing assembly.
 11. The apparatus of claim 8 furthercomprising:a handle connected to the eccentric support for turning theeccentric support, and a selectively engageable lock operativelyconnected to said handle for locking said handle and eccentric supportin place.
 12. The apparatus of claim 8 wherein said belt drivingmechanism includes a drive gear and said orbital drive mechanism isformed by an interconnection of said drive gear with a main gear, saiddrive gear and said main gear being sealed in a casing containinglubricating fluid.
 13. An abrading apparatus for cleaning an outersurface of an elongate member, the apparatus comprising:an elongatesupport for supporting said elongate member; an endless belt having anabrasive surface and mounted for rotation between a pair of spaced apartrollers such that said abrasive surface is disposed adjacent saidelongate support; a belt driving mechanism operatively connected to saidrollers for rotating said rollers and said belt; an orbital drivemechanism connected to said rollers for rotating said endless belt andsaid rollers about said elongate member; and, wherein one of saidrollers includes an eccentric mounting portion and a belt releasemechanism is connected to said eccentric mounting portion to allowrotation of said eccentric mounting portion in two directions, wherebyrotation in one direction moves said one roller toward the other rollerto a belt release position and rotation in an opposite direction movessaid one roller away from the other roller to a belt engagementposition.
 14. The apparatus of claim 13 further comprising a linkageassembly connected to said eccentric mounting portion, wherein pivotingof said linkage assembly rotates said eccentric mounting portion. 15.The apparatus of claim 14 further comprising a handle connected to saidlinkage assembly.
 16. The apparatus of claim 15 wherein said handle ispivotally mounted to a handle support and said linkage assembly includesa first link connected to said eccentric mounting portion and a secondlink pivotally connected between said first link and said handle. 17.The apparatus of claim 16 further comprising a spring connected betweensaid first link and said handle.
 18. The apparatus of claim 13 whereinsaid belt driving mechanism includes a drive gear and said orbital drivemechanism is formed by an interconnection of said drive gear with a maingear, said drive gear and said main gear being sealed in a casingcontaining lubricating fluid.